What does the other person see once they are added as a Collaborator?

A collaborator will have the ability to see all details of the main task they have been added to. They will be able to see any files added to the task and they will also be able to see messages that you have included them on. Collaborators can NOT see private files. In order for a collaborator to see the sub-task details, they will need to be added as a collaborator to each sub-task as well.